Mechanical pencil lead sharpener



MECHANICAL PENCIL LEAD SHARPENER Filed March 1, 1941 6E1? reaps 5. 6/7007} Patented Jan. 13, 1942 UNITED STATES PATENT OFFICE MECHANICAL PENCIL LEAD SHARPENER Gertrude E. Cadet, New York, N. Y.

Application March 1, 1941, Serial No. 381,281

Claims.

This invention is an improvement in sharpeners for the lead of mechanical pencils. The invention comprises a knife or cutter holder, such as a block of suitable material, provided with a hollow passageway for receiving th end of the pencil. This passageway is narrowed to limit the inward movement of the end of the pencil, and just below such narrowed portion, the passage is narrowed still further, to form a space for the lead. Projecting into this space for the lead are one or more knives or cutters for the lead, which, when the pencil is twisted, with slight downward pressure, will shave the lead to a fine conical point.

The sharpener of the present invention is always carried by the pencil and so is always available. To this end, it may be mounted in a cylindrical sleeve, which sleeve is detachably mounted on the eraser end of the pencil. This sleeve carries the usual eraser.

Further details of the improved sharpener will be described in connection. with the accompanying drawing, illustrating the present preferred embodiment of the invention. In the drawing:

Fig. l is a vertical, sectional, perspective View of the sharpener of th present invention;

Fig. 2 is a longitudinal sectional view, on a smaller scale, of the sharpener in place on the pencil.

The sharpener comprises a block of any suitable material M, preferably cylindrical, provided with a central passageway A, of a size and shape to receive the end of the mechanical pencil. The lower part of the passageway is narrowed, as by an inwardly projecting annular shoulder B, for limiting the inward movement of the end of the pencil. Suitably held in the block of material M, are one or more knives C, provided with converging diagonal cutting edges C', these cutting edges being just below the shoulder B and in position to shave the lead of the pencil to a fine conical point. The blades or knives C, C may be held in place in block M in any desired manner, as, for example by friction and are independently adjustable radially, whereby the cutting action of the knives can be controlled by setting them in proper adjusted position.

Just below the knives is a passage D for the escape of the powder resulting from the sharpening.

The sharpener is mounted on the end of the mechanical pencil P so as to be readily available, and to thi end the sharpener is carried in a cylindrical sleeve S, the usual eraser E being mounted in the other end of the cylinder, sleeve S being detachably mounted on th end of pencil P.

In operation, sleeve S is removed from the pencil, the other end of the pen-cil is inserted in passageway A, until the blunt lead engages the knives and then the pencil is rotated with slight downward pressure, thereby shaving the lead 1: a fine conical point.

I claim:

1. A pencil sharpener for the lead of a mechanical pencil, comprising a block of material, provided with a longitudinal guiding recess for receiving the end of the pencil, and knife means provided with a diagonal cutting edge mounted in and carried by said block beyond said recess, for operatively engaging with the lead of the pencil when the pencil is inserted in said recess.

2. A pencil sharpener for the lead of a mechanical pencil, comprising a block of material, provided with a longitudinal guiding recess for receiving the end of the pencil, said block being provided with an inwardly extending shoulder at the inner end of said longitudinal recess, for limiting the inward movement of the pencil, knife means provided with a diagonal cutting edge mounted in and carried by said block just beyond said shoulder, for operatively engaging with the lead of the pencil when the pencil is inserted in said recess, against said shoulder.

3. A pencil sharpener for the lead of a mechanical pencil, comprising a block of material, provided with a longitudinal guiding recess for receiving the end of the pencil, said block being provided with an inwardly extending shoulder at the inner end of said longitudinal recess, for limiting the inward movement of the pencil, radially extending knives provided with diagonal cutting edges at their inner ends mounted in and carried by said block just beyond said shoulder, for operatively engaging with the lead of the pencil when the pencil is inserted in said recess, against said shoulder.

4. A pencil sharpener for the lead of a mechanical pencil, comprising a block of material, provided with a longitudinal guiding recess for receiving the end of the pencil, said block being provided with an inwardly extending shoulder at the inner end of said longitudinal recess, for limiting the inward movement of the pencil, radially extending, individually adjustable knives provided with diagonal cutting edges at their inner ends mounted in and carried by said block just beyond said shoulder, for operatively engaging with the lead of the pencil when the pencil is inserted in said recess, against said shoulder.

5. A pencil sharpener for the lead of a mechanical pencil, comprising a block of material provided with a recess for receiving the end of the mechanical pencil, and radially adjustable knife means, carried by the block of material, just beyond said recess, in a position to engage with the lead of the pencil.

GERTRUDE E. CADOT. 

